Filtration And Overtstocking

[andywg]

I am reminded of a time when everyone knew the world was flat too. At least I have read about it, I am not quite that old.

Given that such a time has never existed, I can understand why you do not remember it The belief that most people at some point within the last 2,000 years thought the world was flat is historically inaccurate. At least since the time of the Greeks we have known that the world was pretty much a sphere but in Victorian times the myth of the dark ages having so little scientific knowledge that they thought the world was flat entered popular belief.

 

[OldMan47]

Thanks for that search Andy. I have not bothered doing one because I am a very practical person, not a scientific one. If frequent large water changes give me better fry growth, I really don't care why. It seems that you have arrived at the same point that I have, or close to it, there is no real evidence that there is any hormone present in the water that inhibits fish growth but good water quality, as represented by frequent water changes, does promote better fry growth. I am not certain what your observation about a closed water loop may mean in terms of fry growth.

 

[andywg]

The point about the closed water system is that systems designed to process nitrates can grow fish at a commercial rate (that is, as quickly as economically possible to get them ready for sale) without the need for water changes. If a hormone was present then one would expect it to accumulate and exhibit problems in such a system.

 

[raptorrex]

Thanks for that search Andy. I have not bothered doing one because I am a very practical person, not a scientific one. If frequent large water changes give me better fry growth, I really don't care why. It seems that you have arrived at the same point that I have, or close to it, there is no real evidence that there is any hormone present in the water that inhibits fish growth but good water quality, as represented by frequent water changes, does promote better fry growth. I am not certain what your observation about a closed water loop may mean in terms of fry growth.

to me, as you say, it does not matter. as long as, your, system allows the fry to thrive, does it really matter why (in the general scheme of things)? for most, that's all we want.
but closed systems and extremely high stocking ratios, all work well in commercial fisheries. these systems would, seem, to give the lie to the growth hormone theory. even with no science, that much is obvious.